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1
/*
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 * WMA compatible decoder
3
 * Copyright (c) 2002 The FFmpeg Project.
4
 *
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 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
19

    
20
/**
21
 * @file wmadec.c
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 * WMA compatible decoder.
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 * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.
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 * WMA v1 is identified by audio format 0x160 in Microsoft media files
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 * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
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 *
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 * To use this decoder, a calling application must supply the extra data
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 * bytes provided with the WMA data. These are the extra, codec-specific
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 * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
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 * to the decoder using the extradata[_size] fields in AVCodecContext. There
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 * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.
32
 */
33

    
34
#include "avcodec.h"
35
#include "bitstream.h"
36
#include "dsputil.h"
37

    
38
/* size of blocks */
39
#define BLOCK_MIN_BITS 7
40
#define BLOCK_MAX_BITS 11
41
#define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
42

    
43
#define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
44

    
45
/* XXX: find exact max size */
46
#define HIGH_BAND_MAX_SIZE 16
47

    
48
#define NB_LSP_COEFS 10
49

    
50
/* XXX: is it a suitable value ? */
51
#define MAX_CODED_SUPERFRAME_SIZE 16384
52

    
53
#define MAX_CHANNELS 2
54

    
55
#define NOISE_TAB_SIZE 8192
56

    
57
#define LSP_POW_BITS 7
58

    
59
#define VLCBITS 9
60
#define VLCMAX ((22+VLCBITS-1)/VLCBITS)
61

    
62
#define EXPVLCBITS 8
63
#define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
64

    
65
#define HGAINVLCBITS 9
66
#define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
67

    
68
typedef struct WMADecodeContext {
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    GetBitContext gb;
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    int sample_rate;
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    int nb_channels;
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    int bit_rate;
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    int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
74
    int block_align;
75
    int use_bit_reservoir;
76
    int use_variable_block_len;
77
    int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
78
    int use_noise_coding; /* true if perceptual noise is added */
79
    int byte_offset_bits;
80
    VLC exp_vlc;
81
    int exponent_sizes[BLOCK_NB_SIZES];
82
    uint16_t exponent_bands[BLOCK_NB_SIZES][25];
83
    int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
84
    int coefs_start;               /* first coded coef */
85
    int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
86
    int exponent_high_sizes[BLOCK_NB_SIZES];
87
    int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
88
    VLC hgain_vlc;
89

    
90
    /* coded values in high bands */
91
    int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
92
    int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
93

    
94
    /* there are two possible tables for spectral coefficients */
95
    VLC coef_vlc[2];
96
    uint16_t *run_table[2];
97
    uint16_t *level_table[2];
98
    /* frame info */
99
    int frame_len;       /* frame length in samples */
100
    int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
101
    int nb_block_sizes;  /* number of block sizes */
102
    /* block info */
103
    int reset_block_lengths;
104
    int block_len_bits; /* log2 of current block length */
105
    int next_block_len_bits; /* log2 of next block length */
106
    int prev_block_len_bits; /* log2 of prev block length */
107
    int block_len; /* block length in samples */
108
    int block_num; /* block number in current frame */
109
    int block_pos; /* current position in frame */
110
    uint8_t ms_stereo; /* true if mid/side stereo mode */
111
    uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
112
    DECLARE_ALIGNED_16(float, exponents[MAX_CHANNELS][BLOCK_MAX_SIZE]);
113
    float max_exponent[MAX_CHANNELS];
114
    int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
115
    DECLARE_ALIGNED_16(float, coefs[MAX_CHANNELS][BLOCK_MAX_SIZE]);
116
    MDCTContext mdct_ctx[BLOCK_NB_SIZES];
117
    float *windows[BLOCK_NB_SIZES];
118
    DECLARE_ALIGNED_16(FFTSample, mdct_tmp[BLOCK_MAX_SIZE]); /* temporary storage for imdct */
119
    /* output buffer for one frame and the last for IMDCT windowing */
120
    DECLARE_ALIGNED_16(float, frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2]);
121
    /* last frame info */
122
    uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
123
    int last_bitoffset;
124
    int last_superframe_len;
125
    float noise_table[NOISE_TAB_SIZE];
126
    int noise_index;
127
    float noise_mult; /* XXX: suppress that and integrate it in the noise array */
128
    /* lsp_to_curve tables */
129
    float lsp_cos_table[BLOCK_MAX_SIZE];
130
    float lsp_pow_e_table[256];
131
    float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
132
    float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
133

    
134
#ifdef TRACE
135
    int frame_count;
136
#endif
137
} WMADecodeContext;
138

    
139
typedef struct CoefVLCTable {
140
    int n; /* total number of codes */
141
    const uint32_t *huffcodes; /* VLC bit values */
142
    const uint8_t *huffbits;   /* VLC bit size */
143
    const uint16_t *levels; /* table to build run/level tables */
144
} CoefVLCTable;
145

    
146
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
147

    
148
#include "wmadata.h"
149

    
150
#ifdef TRACE
151
static void dump_shorts(const char *name, const short *tab, int n)
152
{
153
    int i;
154

    
155
    tprintf("%s[%d]:\n", name, n);
156
    for(i=0;i<n;i++) {
157
        if ((i & 7) == 0)
158
            tprintf("%4d: ", i);
159
        tprintf(" %5d.0", tab[i]);
160
        if ((i & 7) == 7)
161
            tprintf("\n");
162
    }
163
}
164

    
165
static void dump_floats(const char *name, int prec, const float *tab, int n)
166
{
167
    int i;
168

    
169
    tprintf("%s[%d]:\n", name, n);
170
    for(i=0;i<n;i++) {
171
        if ((i & 7) == 0)
172
            tprintf("%4d: ", i);
173
        tprintf(" %8.*f", prec, tab[i]);
174
        if ((i & 7) == 7)
175
            tprintf("\n");
176
    }
177
    if ((i & 7) != 0)
178
        tprintf("\n");
179
}
180
#endif
181

    
182
/* XXX: use same run/length optimization as mpeg decoders */
183
static void init_coef_vlc(VLC *vlc,
184
                          uint16_t **prun_table, uint16_t **plevel_table,
185
                          const CoefVLCTable *vlc_table)
186
{
187
    int n = vlc_table->n;
188
    const uint8_t *table_bits = vlc_table->huffbits;
189
    const uint32_t *table_codes = vlc_table->huffcodes;
190
    const uint16_t *levels_table = vlc_table->levels;
191
    uint16_t *run_table, *level_table;
192
    const uint16_t *p;
193
    int i, l, j, level;
194

    
195
    init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
196

    
197
    run_table = av_malloc(n * sizeof(uint16_t));
198
    level_table = av_malloc(n * sizeof(uint16_t));
199
    p = levels_table;
200
    i = 2;
201
    level = 1;
202
    while (i < n) {
203
        l = *p++;
204
        for(j=0;j<l;j++) {
205
            run_table[i] = j;
206
            level_table[i] = level;
207
            i++;
208
        }
209
        level++;
210
    }
211
    *prun_table = run_table;
212
    *plevel_table = level_table;
213
}
214

    
215
static int wma_decode_init(AVCodecContext * avctx)
216
{
217
    WMADecodeContext *s = avctx->priv_data;
218
    int i, flags1, flags2;
219
    float *window;
220
    uint8_t *extradata;
221
    float bps1, high_freq;
222
    volatile float bps;
223
    int sample_rate1;
224
    int coef_vlc_table;
225

    
226
    s->sample_rate = avctx->sample_rate;
227
    s->nb_channels = avctx->channels;
228
    s->bit_rate = avctx->bit_rate;
229
    s->block_align = avctx->block_align;
230

    
231
    if (avctx->codec->id == CODEC_ID_WMAV1) {
232
        s->version = 1;
233
    } else {
234
        s->version = 2;
235
    }
236

    
237
    /* extract flag infos */
238
    flags1 = 0;
239
    flags2 = 0;
240
    extradata = avctx->extradata;
241
    if (s->version == 1 && avctx->extradata_size >= 4) {
242
        flags1 = extradata[0] | (extradata[1] << 8);
243
        flags2 = extradata[2] | (extradata[3] << 8);
244
    } else if (s->version == 2 && avctx->extradata_size >= 6) {
245
        flags1 = extradata[0] | (extradata[1] << 8) |
246
            (extradata[2] << 16) | (extradata[3] << 24);
247
        flags2 = extradata[4] | (extradata[5] << 8);
248
    }
249
    s->use_exp_vlc = flags2 & 0x0001;
250
    s->use_bit_reservoir = flags2 & 0x0002;
251
    s->use_variable_block_len = flags2 & 0x0004;
252

    
253
    /* compute MDCT block size */
254
    if (s->sample_rate <= 16000) {
255
        s->frame_len_bits = 9;
256
    } else if (s->sample_rate <= 22050 ||
257
               (s->sample_rate <= 32000 && s->version == 1)) {
258
        s->frame_len_bits = 10;
259
    } else {
260
        s->frame_len_bits = 11;
261
    }
262
    s->frame_len = 1 << s->frame_len_bits;
263
    if (s->use_variable_block_len) {
264
        int nb_max, nb;
265
        nb = ((flags2 >> 3) & 3) + 1;
266
        if ((s->bit_rate / s->nb_channels) >= 32000)
267
            nb += 2;
268
        nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
269
        if (nb > nb_max)
270
            nb = nb_max;
271
        s->nb_block_sizes = nb + 1;
272
    } else {
273
        s->nb_block_sizes = 1;
274
    }
275

    
276
    /* init rate dependant parameters */
277
    s->use_noise_coding = 1;
278
    high_freq = s->sample_rate * 0.5;
279

    
280
    /* if version 2, then the rates are normalized */
281
    sample_rate1 = s->sample_rate;
282
    if (s->version == 2) {
283
        if (sample_rate1 >= 44100)
284
            sample_rate1 = 44100;
285
        else if (sample_rate1 >= 22050)
286
            sample_rate1 = 22050;
287
        else if (sample_rate1 >= 16000)
288
            sample_rate1 = 16000;
289
        else if (sample_rate1 >= 11025)
290
            sample_rate1 = 11025;
291
        else if (sample_rate1 >= 8000)
292
            sample_rate1 = 8000;
293
    }
294

    
295
    bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
296
    s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
297

    
298
    /* compute high frequency value and choose if noise coding should
299
       be activated */
300
    bps1 = bps;
301
    if (s->nb_channels == 2)
302
        bps1 = bps * 1.6;
303
    if (sample_rate1 == 44100) {
304
        if (bps1 >= 0.61)
305
            s->use_noise_coding = 0;
306
        else
307
            high_freq = high_freq * 0.4;
308
    } else if (sample_rate1 == 22050) {
309
        if (bps1 >= 1.16)
310
            s->use_noise_coding = 0;
311
        else if (bps1 >= 0.72)
312
            high_freq = high_freq * 0.7;
313
        else
314
            high_freq = high_freq * 0.6;
315
    } else if (sample_rate1 == 16000) {
316
        if (bps > 0.5)
317
            high_freq = high_freq * 0.5;
318
        else
319
            high_freq = high_freq * 0.3;
320
    } else if (sample_rate1 == 11025) {
321
        high_freq = high_freq * 0.7;
322
    } else if (sample_rate1 == 8000) {
323
        if (bps <= 0.625) {
324
            high_freq = high_freq * 0.5;
325
        } else if (bps > 0.75) {
326
            s->use_noise_coding = 0;
327
        } else {
328
            high_freq = high_freq * 0.65;
329
        }
330
    } else {
331
        if (bps >= 0.8) {
332
            high_freq = high_freq * 0.75;
333
        } else if (bps >= 0.6) {
334
            high_freq = high_freq * 0.6;
335
        } else {
336
            high_freq = high_freq * 0.5;
337
        }
338
    }
339
    dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
340
    dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
341
           s->version, s->nb_channels, s->sample_rate, s->bit_rate,
342
           s->block_align);
343
    dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
344
           bps, bps1, high_freq, s->byte_offset_bits);
345
    dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
346
           s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
347

    
348
    /* compute the scale factor band sizes for each MDCT block size */
349
    {
350
        int a, b, pos, lpos, k, block_len, i, j, n;
351
        const uint8_t *table;
352

    
353
        if (s->version == 1) {
354
            s->coefs_start = 3;
355
        } else {
356
            s->coefs_start = 0;
357
        }
358
        for(k = 0; k < s->nb_block_sizes; k++) {
359
            block_len = s->frame_len >> k;
360

    
361
            if (s->version == 1) {
362
                lpos = 0;
363
                for(i=0;i<25;i++) {
364
                    a = wma_critical_freqs[i];
365
                    b = s->sample_rate;
366
                    pos = ((block_len * 2 * a)  + (b >> 1)) / b;
367
                    if (pos > block_len)
368
                        pos = block_len;
369
                    s->exponent_bands[0][i] = pos - lpos;
370
                    if (pos >= block_len) {
371
                        i++;
372
                        break;
373
                    }
374
                    lpos = pos;
375
                }
376
                s->exponent_sizes[0] = i;
377
            } else {
378
                /* hardcoded tables */
379
                table = NULL;
380
                a = s->frame_len_bits - BLOCK_MIN_BITS - k;
381
                if (a < 3) {
382
                    if (s->sample_rate >= 44100)
383
                        table = exponent_band_44100[a];
384
                    else if (s->sample_rate >= 32000)
385
                        table = exponent_band_32000[a];
386
                    else if (s->sample_rate >= 22050)
387
                        table = exponent_band_22050[a];
388
                }
389
                if (table) {
390
                    n = *table++;
391
                    for(i=0;i<n;i++)
392
                        s->exponent_bands[k][i] = table[i];
393
                    s->exponent_sizes[k] = n;
394
                } else {
395
                    j = 0;
396
                    lpos = 0;
397
                    for(i=0;i<25;i++) {
398
                        a = wma_critical_freqs[i];
399
                        b = s->sample_rate;
400
                        pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
401
                        pos <<= 2;
402
                        if (pos > block_len)
403
                            pos = block_len;
404
                        if (pos > lpos)
405
                            s->exponent_bands[k][j++] = pos - lpos;
406
                        if (pos >= block_len)
407
                            break;
408
                        lpos = pos;
409
                    }
410
                    s->exponent_sizes[k] = j;
411
                }
412
            }
413

    
414
            /* max number of coefs */
415
            s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
416
            /* high freq computation */
417
            s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
418
                                          s->sample_rate + 0.5);
419
            n = s->exponent_sizes[k];
420
            j = 0;
421
            pos = 0;
422
            for(i=0;i<n;i++) {
423
                int start, end;
424
                start = pos;
425
                pos += s->exponent_bands[k][i];
426
                end = pos;
427
                if (start < s->high_band_start[k])
428
                    start = s->high_band_start[k];
429
                if (end > s->coefs_end[k])
430
                    end = s->coefs_end[k];
431
                if (end > start)
432
                    s->exponent_high_bands[k][j++] = end - start;
433
            }
434
            s->exponent_high_sizes[k] = j;
435
#if 0
436
            tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
437
                  s->frame_len >> k,
438
                  s->coefs_end[k],
439
                  s->high_band_start[k],
440
                  s->exponent_high_sizes[k]);
441
            for(j=0;j<s->exponent_high_sizes[k];j++)
442
                tprintf(" %d", s->exponent_high_bands[k][j]);
443
            tprintf("\n");
444
#endif
445
        }
446
    }
447

    
448
#ifdef TRACE
449
    {
450
        int i, j;
451
        for(i = 0; i < s->nb_block_sizes; i++) {
452
            tprintf("%5d: n=%2d:",
453
                   s->frame_len >> i,
454
                   s->exponent_sizes[i]);
455
            for(j=0;j<s->exponent_sizes[i];j++)
456
                tprintf(" %d", s->exponent_bands[i][j]);
457
            tprintf("\n");
458
        }
459
    }
460
#endif
461

    
462
    /* init MDCT */
463
    for(i = 0; i < s->nb_block_sizes; i++)
464
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
465

    
466
    /* init MDCT windows : simple sinus window */
467
    for(i = 0; i < s->nb_block_sizes; i++) {
468
        int n, j;
469
        float alpha;
470
        n = 1 << (s->frame_len_bits - i);
471
        window = av_malloc(sizeof(float) * n);
472
        alpha = M_PI / (2.0 * n);
473
        for(j=0;j<n;j++) {
474
            window[n - j - 1] = sin((j + 0.5) * alpha);
475
        }
476
        s->windows[i] = window;
477
    }
478

    
479
    s->reset_block_lengths = 1;
480

    
481
    if (s->use_noise_coding) {
482

    
483
        /* init the noise generator */
484
        if (s->use_exp_vlc)
485
            s->noise_mult = 0.02;
486
        else
487
            s->noise_mult = 0.04;
488

    
489
#ifdef TRACE
490
        for(i=0;i<NOISE_TAB_SIZE;i++)
491
            s->noise_table[i] = 1.0 * s->noise_mult;
492
#else
493
        {
494
            unsigned int seed;
495
            float norm;
496
            seed = 1;
497
            norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
498
            for(i=0;i<NOISE_TAB_SIZE;i++) {
499
                seed = seed * 314159 + 1;
500
                s->noise_table[i] = (float)((int)seed) * norm;
501
            }
502
        }
503
#endif
504
        init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(hgain_huffbits),
505
                 hgain_huffbits, 1, 1,
506
                 hgain_huffcodes, 2, 2, 0);
507
    }
508

    
509
    if (s->use_exp_vlc) {
510
        init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(scale_huffbits),
511
                 scale_huffbits, 1, 1,
512
                 scale_huffcodes, 4, 4, 0);
513
    } else {
514
        wma_lsp_to_curve_init(s, s->frame_len);
515
    }
516

    
517
    /* choose the VLC tables for the coefficients */
518
    coef_vlc_table = 2;
519
    if (s->sample_rate >= 32000) {
520
        if (bps1 < 0.72)
521
            coef_vlc_table = 0;
522
        else if (bps1 < 1.16)
523
            coef_vlc_table = 1;
524
    }
525

    
526
    init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
527
                  &coef_vlcs[coef_vlc_table * 2]);
528
    init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
529
                  &coef_vlcs[coef_vlc_table * 2 + 1]);
530
    return 0;
531
}
532

    
533
/* interpolate values for a bigger or smaller block. The block must
534
   have multiple sizes */
535
static void interpolate_array(float *scale, int old_size, int new_size)
536
{
537
    int i, j, jincr, k;
538
    float v;
539

    
540
    if (new_size > old_size) {
541
        jincr = new_size / old_size;
542
        j = new_size;
543
        for(i = old_size - 1; i >=0; i--) {
544
            v = scale[i];
545
            k = jincr;
546
            do {
547
                scale[--j] = v;
548
            } while (--k);
549
        }
550
    } else if (new_size < old_size) {
551
        j = 0;
552
        jincr = old_size / new_size;
553
        for(i = 0; i < new_size; i++) {
554
            scale[i] = scale[j];
555
            j += jincr;
556
        }
557
    }
558
}
559

    
560
/* compute x^-0.25 with an exponent and mantissa table. We use linear
561
   interpolation to reduce the mantissa table size at a small speed
562
   expense (linear interpolation approximately doubles the number of
563
   bits of precision). */
564
static inline float pow_m1_4(WMADecodeContext *s, float x)
565
{
566
    union {
567
        float f;
568
        unsigned int v;
569
    } u, t;
570
    unsigned int e, m;
571
    float a, b;
572

    
573
    u.f = x;
574
    e = u.v >> 23;
575
    m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
576
    /* build interpolation scale: 1 <= t < 2. */
577
    t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
578
    a = s->lsp_pow_m_table1[m];
579
    b = s->lsp_pow_m_table2[m];
580
    return s->lsp_pow_e_table[e] * (a + b * t.f);
581
}
582

    
583
static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
584
{
585
    float wdel, a, b;
586
    int i, e, m;
587

    
588
    wdel = M_PI / frame_len;
589
    for(i=0;i<frame_len;i++)
590
        s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
591

    
592
    /* tables for x^-0.25 computation */
593
    for(i=0;i<256;i++) {
594
        e = i - 126;
595
        s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
596
    }
597

    
598
    /* NOTE: these two tables are needed to avoid two operations in
599
       pow_m1_4 */
600
    b = 1.0;
601
    for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
602
        m = (1 << LSP_POW_BITS) + i;
603
        a = (float)m * (0.5 / (1 << LSP_POW_BITS));
604
        a = pow(a, -0.25);
605
        s->lsp_pow_m_table1[i] = 2 * a - b;
606
        s->lsp_pow_m_table2[i] = b - a;
607
        b = a;
608
    }
609
#if 0
610
    for(i=1;i<20;i++) {
611
        float v, r1, r2;
612
        v = 5.0 / i;
613
        r1 = pow_m1_4(s, v);
614
        r2 = pow(v,-0.25);
615
        printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
616
    }
617
#endif
618
}
619

    
620
/* NOTE: We use the same code as Vorbis here */
621
/* XXX: optimize it further with SSE/3Dnow */
622
static void wma_lsp_to_curve(WMADecodeContext *s,
623
                             float *out, float *val_max_ptr,
624
                             int n, float *lsp)
625
{
626
    int i, j;
627
    float p, q, w, v, val_max;
628

    
629
    val_max = 0;
630
    for(i=0;i<n;i++) {
631
        p = 0.5f;
632
        q = 0.5f;
633
        w = s->lsp_cos_table[i];
634
        for(j=1;j<NB_LSP_COEFS;j+=2){
635
            q *= w - lsp[j - 1];
636
            p *= w - lsp[j];
637
        }
638
        p *= p * (2.0f - w);
639
        q *= q * (2.0f + w);
640
        v = p + q;
641
        v = pow_m1_4(s, v);
642
        if (v > val_max)
643
            val_max = v;
644
        out[i] = v;
645
    }
646
    *val_max_ptr = val_max;
647
}
648

    
649
/* decode exponents coded with LSP coefficients (same idea as Vorbis) */
650
static void decode_exp_lsp(WMADecodeContext *s, int ch)
651
{
652
    float lsp_coefs[NB_LSP_COEFS];
653
    int val, i;
654

    
655
    for(i = 0; i < NB_LSP_COEFS; i++) {
656
        if (i == 0 || i >= 8)
657
            val = get_bits(&s->gb, 3);
658
        else
659
            val = get_bits(&s->gb, 4);
660
        lsp_coefs[i] = lsp_codebook[i][val];
661
    }
662

    
663
    wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
664
                     s->block_len, lsp_coefs);
665
}
666

    
667
/* decode exponents coded with VLC codes */
668
static int decode_exp_vlc(WMADecodeContext *s, int ch)
669
{
670
    int last_exp, n, code;
671
    const uint16_t *ptr, *band_ptr;
672
    float v, *q, max_scale, *q_end;
673

    
674
    band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
675
    ptr = band_ptr;
676
    q = s->exponents[ch];
677
    q_end = q + s->block_len;
678
    max_scale = 0;
679
    if (s->version == 1) {
680
        last_exp = get_bits(&s->gb, 5) + 10;
681
        /* XXX: use a table */
682
        v = pow(10, last_exp * (1.0 / 16.0));
683
        max_scale = v;
684
        n = *ptr++;
685
        do {
686
            *q++ = v;
687
        } while (--n);
688
    }
689
    last_exp = 36;
690
    while (q < q_end) {
691
        code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
692
        if (code < 0)
693
            return -1;
694
        /* NOTE: this offset is the same as MPEG4 AAC ! */
695
        last_exp += code - 60;
696
        /* XXX: use a table */
697
        v = pow(10, last_exp * (1.0 / 16.0));
698
        if (v > max_scale)
699
            max_scale = v;
700
        n = *ptr++;
701
        do {
702
            *q++ = v;
703
        } while (--n);
704
    }
705
    s->max_exponent[ch] = max_scale;
706
    return 0;
707
}
708

    
709
/* return 0 if OK. return 1 if last block of frame. return -1 if
710
   unrecorrable error. */
711
static int wma_decode_block(WMADecodeContext *s)
712
{
713
    int n, v, a, ch, code, bsize;
714
    int coef_nb_bits, total_gain, parse_exponents;
715
    float window[BLOCK_MAX_SIZE * 2];
716
// XXX: FIXME!! there's a bug somewhere which makes this mandatory under altivec
717
#ifdef HAVE_ALTIVEC
718
    volatile int nb_coefs[MAX_CHANNELS] __attribute__((aligned(16)));
719
#else
720
    int nb_coefs[MAX_CHANNELS];
721
#endif
722
    float mdct_norm;
723

    
724
#ifdef TRACE
725
    tprintf("***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
726
#endif
727

    
728
    /* compute current block length */
729
    if (s->use_variable_block_len) {
730
        n = av_log2(s->nb_block_sizes - 1) + 1;
731

    
732
        if (s->reset_block_lengths) {
733
            s->reset_block_lengths = 0;
734
            v = get_bits(&s->gb, n);
735
            if (v >= s->nb_block_sizes)
736
                return -1;
737
            s->prev_block_len_bits = s->frame_len_bits - v;
738
            v = get_bits(&s->gb, n);
739
            if (v >= s->nb_block_sizes)
740
                return -1;
741
            s->block_len_bits = s->frame_len_bits - v;
742
        } else {
743
            /* update block lengths */
744
            s->prev_block_len_bits = s->block_len_bits;
745
            s->block_len_bits = s->next_block_len_bits;
746
        }
747
        v = get_bits(&s->gb, n);
748
        if (v >= s->nb_block_sizes)
749
            return -1;
750
        s->next_block_len_bits = s->frame_len_bits - v;
751
    } else {
752
        /* fixed block len */
753
        s->next_block_len_bits = s->frame_len_bits;
754
        s->prev_block_len_bits = s->frame_len_bits;
755
        s->block_len_bits = s->frame_len_bits;
756
    }
757

    
758
    /* now check if the block length is coherent with the frame length */
759
    s->block_len = 1 << s->block_len_bits;
760
    if ((s->block_pos + s->block_len) > s->frame_len)
761
        return -1;
762

    
763
    if (s->nb_channels == 2) {
764
        s->ms_stereo = get_bits(&s->gb, 1);
765
    }
766
    v = 0;
767
    for(ch = 0; ch < s->nb_channels; ch++) {
768
        a = get_bits(&s->gb, 1);
769
        s->channel_coded[ch] = a;
770
        v |= a;
771
    }
772
    /* if no channel coded, no need to go further */
773
    /* XXX: fix potential framing problems */
774
    if (!v)
775
        goto next;
776

    
777
    bsize = s->frame_len_bits - s->block_len_bits;
778

    
779
    /* read total gain and extract corresponding number of bits for
780
       coef escape coding */
781
    total_gain = 1;
782
    for(;;) {
783
        a = get_bits(&s->gb, 7);
784
        total_gain += a;
785
        if (a != 127)
786
            break;
787
    }
788

    
789
    if (total_gain < 15)
790
        coef_nb_bits = 13;
791
    else if (total_gain < 32)
792
        coef_nb_bits = 12;
793
    else if (total_gain < 40)
794
        coef_nb_bits = 11;
795
    else if (total_gain < 45)
796
        coef_nb_bits = 10;
797
    else
798
        coef_nb_bits = 9;
799

    
800
    /* compute number of coefficients */
801
    n = s->coefs_end[bsize] - s->coefs_start;
802
    for(ch = 0; ch < s->nb_channels; ch++)
803
        nb_coefs[ch] = n;
804

    
805
    /* complex coding */
806
    if (s->use_noise_coding) {
807

    
808
        for(ch = 0; ch < s->nb_channels; ch++) {
809
            if (s->channel_coded[ch]) {
810
                int i, n, a;
811
                n = s->exponent_high_sizes[bsize];
812
                for(i=0;i<n;i++) {
813
                    a = get_bits(&s->gb, 1);
814
                    s->high_band_coded[ch][i] = a;
815
                    /* if noise coding, the coefficients are not transmitted */
816
                    if (a)
817
                        nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
818
                }
819
            }
820
        }
821
        for(ch = 0; ch < s->nb_channels; ch++) {
822
            if (s->channel_coded[ch]) {
823
                int i, n, val, code;
824

    
825
                n = s->exponent_high_sizes[bsize];
826
                val = (int)0x80000000;
827
                for(i=0;i<n;i++) {
828
                    if (s->high_band_coded[ch][i]) {
829
                        if (val == (int)0x80000000) {
830
                            val = get_bits(&s->gb, 7) - 19;
831
                        } else {
832
                            code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
833
                            if (code < 0)
834
                                return -1;
835
                            val += code - 18;
836
                        }
837
                        s->high_band_values[ch][i] = val;
838
                    }
839
                }
840
            }
841
        }
842
    }
843

    
844
    /* exposant can be interpolated in short blocks. */
845
    parse_exponents = 1;
846
    if (s->block_len_bits != s->frame_len_bits) {
847
        parse_exponents = get_bits(&s->gb, 1);
848
    }
849

    
850
    if (parse_exponents) {
851
        for(ch = 0; ch < s->nb_channels; ch++) {
852
            if (s->channel_coded[ch]) {
853
                if (s->use_exp_vlc) {
854
                    if (decode_exp_vlc(s, ch) < 0)
855
                        return -1;
856
                } else {
857
                    decode_exp_lsp(s, ch);
858
                }
859
            }
860
        }
861
    } else {
862
        for(ch = 0; ch < s->nb_channels; ch++) {
863
            if (s->channel_coded[ch]) {
864
                interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
865
                                  s->block_len);
866
            }
867
        }
868
    }
869

    
870
    /* parse spectral coefficients : just RLE encoding */
871
    for(ch = 0; ch < s->nb_channels; ch++) {
872
        if (s->channel_coded[ch]) {
873
            VLC *coef_vlc;
874
            int level, run, sign, tindex;
875
            int16_t *ptr, *eptr;
876
            const int16_t *level_table, *run_table;
877

    
878
            /* special VLC tables are used for ms stereo because
879
               there is potentially less energy there */
880
            tindex = (ch == 1 && s->ms_stereo);
881
            coef_vlc = &s->coef_vlc[tindex];
882
            run_table = s->run_table[tindex];
883
            level_table = s->level_table[tindex];
884
            /* XXX: optimize */
885
            ptr = &s->coefs1[ch][0];
886
            eptr = ptr + nb_coefs[ch];
887
            memset(ptr, 0, s->block_len * sizeof(int16_t));
888
            for(;;) {
889
                code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
890
                if (code < 0)
891
                    return -1;
892
                if (code == 1) {
893
                    /* EOB */
894
                    break;
895
                } else if (code == 0) {
896
                    /* escape */
897
                    level = get_bits(&s->gb, coef_nb_bits);
898
                    /* NOTE: this is rather suboptimal. reading
899
                       block_len_bits would be better */
900
                    run = get_bits(&s->gb, s->frame_len_bits);
901
                } else {
902
                    /* normal code */
903
                    run = run_table[code];
904
                    level = level_table[code];
905
                }
906
                sign = get_bits(&s->gb, 1);
907
                if (!sign)
908
                    level = -level;
909
                ptr += run;
910
                if (ptr >= eptr)
911
                {
912
                    av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
913
                    break;
914
                }
915
                *ptr++ = level;
916
                /* NOTE: EOB can be omitted */
917
                if (ptr >= eptr)
918
                    break;
919
            }
920
        }
921
        if (s->version == 1 && s->nb_channels >= 2) {
922
            align_get_bits(&s->gb);
923
        }
924
    }
925

    
926
    /* normalize */
927
    {
928
        int n4 = s->block_len / 2;
929
        mdct_norm = 1.0 / (float)n4;
930
        if (s->version == 1) {
931
            mdct_norm *= sqrt(n4);
932
        }
933
    }
934

    
935
    /* finally compute the MDCT coefficients */
936
    for(ch = 0; ch < s->nb_channels; ch++) {
937
        if (s->channel_coded[ch]) {
938
            int16_t *coefs1;
939
            float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
940
            int i, j, n, n1, last_high_band;
941
            float exp_power[HIGH_BAND_MAX_SIZE];
942

    
943
            coefs1 = s->coefs1[ch];
944
            exponents = s->exponents[ch];
945
            mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
946
            mult *= mdct_norm;
947
            coefs = s->coefs[ch];
948
            if (s->use_noise_coding) {
949
                mult1 = mult;
950
                /* very low freqs : noise */
951
                for(i = 0;i < s->coefs_start; i++) {
952
                    *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
953
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
954
                }
955

    
956
                n1 = s->exponent_high_sizes[bsize];
957

    
958
                /* compute power of high bands */
959
                exp_ptr = exponents +
960
                    s->high_band_start[bsize] -
961
                    s->coefs_start;
962
                last_high_band = 0; /* avoid warning */
963
                for(j=0;j<n1;j++) {
964
                    n = s->exponent_high_bands[s->frame_len_bits -
965
                                              s->block_len_bits][j];
966
                    if (s->high_band_coded[ch][j]) {
967
                        float e2, v;
968
                        e2 = 0;
969
                        for(i = 0;i < n; i++) {
970
                            v = exp_ptr[i];
971
                            e2 += v * v;
972
                        }
973
                        exp_power[j] = e2 / n;
974
                        last_high_band = j;
975
                        tprintf("%d: power=%f (%d)\n", j, exp_power[j], n);
976
                    }
977
                    exp_ptr += n;
978
                }
979

    
980
                /* main freqs and high freqs */
981
                for(j=-1;j<n1;j++) {
982
                    if (j < 0) {
983
                        n = s->high_band_start[bsize] -
984
                            s->coefs_start;
985
                    } else {
986
                        n = s->exponent_high_bands[s->frame_len_bits -
987
                                                  s->block_len_bits][j];
988
                    }
989
                    if (j >= 0 && s->high_band_coded[ch][j]) {
990
                        /* use noise with specified power */
991
                        mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
992
                        /* XXX: use a table */
993
                        mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
994
                        mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
995
                        mult1 *= mdct_norm;
996
                        for(i = 0;i < n; i++) {
997
                            noise = s->noise_table[s->noise_index];
998
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
999
                            *coefs++ = (*exponents++) * noise * mult1;
1000
                        }
1001
                    } else {
1002
                        /* coded values + small noise */
1003
                        for(i = 0;i < n; i++) {
1004
                            noise = s->noise_table[s->noise_index];
1005
                            s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1006
                            *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
1007
                        }
1008
                    }
1009
                }
1010

    
1011
                /* very high freqs : noise */
1012
                n = s->block_len - s->coefs_end[bsize];
1013
                mult1 = mult * exponents[-1];
1014
                for(i = 0; i < n; i++) {
1015
                    *coefs++ = s->noise_table[s->noise_index] * mult1;
1016
                    s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1017
                }
1018
            } else {
1019
                /* XXX: optimize more */
1020
                for(i = 0;i < s->coefs_start; i++)
1021
                    *coefs++ = 0.0;
1022
                n = nb_coefs[ch];
1023
                for(i = 0;i < n; i++) {
1024
                    *coefs++ = coefs1[i] * exponents[i] * mult;
1025
                }
1026
                n = s->block_len - s->coefs_end[bsize];
1027
                for(i = 0;i < n; i++)
1028
                    *coefs++ = 0.0;
1029
            }
1030
        }
1031
    }
1032

    
1033
#ifdef TRACE
1034
    for(ch = 0; ch < s->nb_channels; ch++) {
1035
        if (s->channel_coded[ch]) {
1036
            dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1037
            dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1038
        }
1039
    }
1040
#endif
1041

    
1042
    if (s->ms_stereo && s->channel_coded[1]) {
1043
        float a, b;
1044
        int i;
1045

    
1046
        /* nominal case for ms stereo: we do it before mdct */
1047
        /* no need to optimize this case because it should almost
1048
           never happen */
1049
        if (!s->channel_coded[0]) {
1050
            tprintf("rare ms-stereo case happened\n");
1051
            memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1052
            s->channel_coded[0] = 1;
1053
        }
1054

    
1055
        for(i = 0; i < s->block_len; i++) {
1056
            a = s->coefs[0][i];
1057
            b = s->coefs[1][i];
1058
            s->coefs[0][i] = a + b;
1059
            s->coefs[1][i] = a - b;
1060
        }
1061
    }
1062

    
1063
    /* build the window : we ensure that when the windows overlap
1064
       their squared sum is always 1 (MDCT reconstruction rule) */
1065
    /* XXX: merge with output */
1066
    {
1067
        int i, next_block_len, block_len, prev_block_len, n;
1068
        float *wptr;
1069

    
1070
        block_len = s->block_len;
1071
        prev_block_len = 1 << s->prev_block_len_bits;
1072
        next_block_len = 1 << s->next_block_len_bits;
1073

    
1074
        /* right part */
1075
        wptr = window + block_len;
1076
        if (block_len <= next_block_len) {
1077
            for(i=0;i<block_len;i++)
1078
                *wptr++ = s->windows[bsize][i];
1079
        } else {
1080
            /* overlap */
1081
            n = (block_len / 2) - (next_block_len / 2);
1082
            for(i=0;i<n;i++)
1083
                *wptr++ = 1.0;
1084
            for(i=0;i<next_block_len;i++)
1085
                *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1086
            for(i=0;i<n;i++)
1087
                *wptr++ = 0.0;
1088
        }
1089

    
1090
        /* left part */
1091
        wptr = window + block_len;
1092
        if (block_len <= prev_block_len) {
1093
            for(i=0;i<block_len;i++)
1094
                *--wptr = s->windows[bsize][i];
1095
        } else {
1096
            /* overlap */
1097
            n = (block_len / 2) - (prev_block_len / 2);
1098
            for(i=0;i<n;i++)
1099
                *--wptr = 1.0;
1100
            for(i=0;i<prev_block_len;i++)
1101
                *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1102
            for(i=0;i<n;i++)
1103
                *--wptr = 0.0;
1104
        }
1105
    }
1106

    
1107

    
1108
    for(ch = 0; ch < s->nb_channels; ch++) {
1109
        if (s->channel_coded[ch]) {
1110
            DECLARE_ALIGNED_16(FFTSample, output[BLOCK_MAX_SIZE * 2]);
1111
            float *ptr;
1112
            int i, n4, index, n;
1113

    
1114
            n = s->block_len;
1115
            n4 = s->block_len / 2;
1116
            ff_imdct_calc(&s->mdct_ctx[bsize],
1117
                          output, s->coefs[ch], s->mdct_tmp);
1118

    
1119
            /* XXX: optimize all that by build the window and
1120
               multipying/adding at the same time */
1121
            /* multiply by the window */
1122
            for(i=0;i<n * 2;i++) {
1123
                output[i] *= window[i];
1124
            }
1125

    
1126
            /* add in the frame */
1127
            index = (s->frame_len / 2) + s->block_pos - n4;
1128
            ptr = &s->frame_out[ch][index];
1129
            for(i=0;i<n * 2;i++) {
1130
                *ptr += output[i];
1131
                ptr++;
1132
            }
1133

    
1134
            /* specific fast case for ms-stereo : add to second
1135
               channel if it is not coded */
1136
            if (s->ms_stereo && !s->channel_coded[1]) {
1137
                ptr = &s->frame_out[1][index];
1138
                for(i=0;i<n * 2;i++) {
1139
                    *ptr += output[i];
1140
                    ptr++;
1141
                }
1142
            }
1143
        }
1144
    }
1145
 next:
1146
    /* update block number */
1147
    s->block_num++;
1148
    s->block_pos += s->block_len;
1149
    if (s->block_pos >= s->frame_len)
1150
        return 1;
1151
    else
1152
        return 0;
1153
}
1154

    
1155
/* decode a frame of frame_len samples */
1156
static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1157
{
1158
    int ret, i, n, a, ch, incr;
1159
    int16_t *ptr;
1160
    float *iptr;
1161

    
1162
#ifdef TRACE
1163
    tprintf("***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
1164
#endif
1165

    
1166
    /* read each block */
1167
    s->block_num = 0;
1168
    s->block_pos = 0;
1169
    for(;;) {
1170
        ret = wma_decode_block(s);
1171
        if (ret < 0)
1172
            return -1;
1173
        if (ret)
1174
            break;
1175
    }
1176

    
1177
    /* convert frame to integer */
1178
    n = s->frame_len;
1179
    incr = s->nb_channels;
1180
    for(ch = 0; ch < s->nb_channels; ch++) {
1181
        ptr = samples + ch;
1182
        iptr = s->frame_out[ch];
1183

    
1184
        for(i=0;i<n;i++) {
1185
            a = lrintf(*iptr++);
1186
            if (a > 32767)
1187
                a = 32767;
1188
            else if (a < -32768)
1189
                a = -32768;
1190
            *ptr = a;
1191
            ptr += incr;
1192
        }
1193
        /* prepare for next block */
1194
        memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1195
                s->frame_len * sizeof(float));
1196
        /* XXX: suppress this */
1197
        memset(&s->frame_out[ch][s->frame_len], 0,
1198
               s->frame_len * sizeof(float));
1199
    }
1200

    
1201
#ifdef TRACE
1202
    dump_shorts("samples", samples, n * s->nb_channels);
1203
#endif
1204
    return 0;
1205
}
1206

    
1207
static int wma_decode_superframe(AVCodecContext *avctx,
1208
                                 void *data, int *data_size,
1209
                                 uint8_t *buf, int buf_size)
1210
{
1211
    WMADecodeContext *s = avctx->priv_data;
1212
    int nb_frames, bit_offset, i, pos, len;
1213
    uint8_t *q;
1214
    int16_t *samples;
1215

    
1216
    tprintf("***decode_superframe:\n");
1217

    
1218
    if(buf_size==0){
1219
        s->last_superframe_len = 0;
1220
        return 0;
1221
    }
1222

    
1223
    samples = data;
1224

    
1225
    init_get_bits(&s->gb, buf, buf_size*8);
1226

    
1227
    if (s->use_bit_reservoir) {
1228
        /* read super frame header */
1229
        get_bits(&s->gb, 4); /* super frame index */
1230
        nb_frames = get_bits(&s->gb, 4) - 1;
1231

    
1232
        bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1233

    
1234
        if (s->last_superframe_len > 0) {
1235
            //        printf("skip=%d\n", s->last_bitoffset);
1236
            /* add bit_offset bits to last frame */
1237
            if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1238
                MAX_CODED_SUPERFRAME_SIZE)
1239
                goto fail;
1240
            q = s->last_superframe + s->last_superframe_len;
1241
            len = bit_offset;
1242
            while (len > 7) {
1243
                *q++ = (get_bits)(&s->gb, 8);
1244
                len -= 8;
1245
            }
1246
            if (len > 0) {
1247
                *q++ = (get_bits)(&s->gb, len) << (8 - len);
1248
            }
1249

    
1250
            /* XXX: bit_offset bits into last frame */
1251
            init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
1252
            /* skip unused bits */
1253
            if (s->last_bitoffset > 0)
1254
                skip_bits(&s->gb, s->last_bitoffset);
1255
            /* this frame is stored in the last superframe and in the
1256
               current one */
1257
            if (wma_decode_frame(s, samples) < 0)
1258
                goto fail;
1259
            samples += s->nb_channels * s->frame_len;
1260
        }
1261

    
1262
        /* read each frame starting from bit_offset */
1263
        pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1264
        init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
1265
        len = pos & 7;
1266
        if (len > 0)
1267
            skip_bits(&s->gb, len);
1268

    
1269
        s->reset_block_lengths = 1;
1270
        for(i=0;i<nb_frames;i++) {
1271
            if (wma_decode_frame(s, samples) < 0)
1272
                goto fail;
1273
            samples += s->nb_channels * s->frame_len;
1274
        }
1275

    
1276
        /* we copy the end of the frame in the last frame buffer */
1277
        pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1278
        s->last_bitoffset = pos & 7;
1279
        pos >>= 3;
1280
        len = buf_size - pos;
1281
        if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1282
            goto fail;
1283
        }
1284
        s->last_superframe_len = len;
1285
        memcpy(s->last_superframe, buf + pos, len);
1286
    } else {
1287
        /* single frame decode */
1288
        if (wma_decode_frame(s, samples) < 0)
1289
            goto fail;
1290
        samples += s->nb_channels * s->frame_len;
1291
    }
1292
    *data_size = (int8_t *)samples - (int8_t *)data;
1293
    return s->block_align;
1294
 fail:
1295
    /* when error, we reset the bit reservoir */
1296
    s->last_superframe_len = 0;
1297
    return -1;
1298
}
1299

    
1300
static int wma_decode_end(AVCodecContext *avctx)
1301
{
1302
    WMADecodeContext *s = avctx->priv_data;
1303
    int i;
1304

    
1305
    for(i = 0; i < s->nb_block_sizes; i++)
1306
        ff_mdct_end(&s->mdct_ctx[i]);
1307
    for(i = 0; i < s->nb_block_sizes; i++)
1308
        av_free(s->windows[i]);
1309

    
1310
    if (s->use_exp_vlc) {
1311
        free_vlc(&s->exp_vlc);
1312
    }
1313
    if (s->use_noise_coding) {
1314
        free_vlc(&s->hgain_vlc);
1315
    }
1316
    for(i = 0;i < 2; i++) {
1317
        free_vlc(&s->coef_vlc[i]);
1318
        av_free(s->run_table[i]);
1319
        av_free(s->level_table[i]);
1320
    }
1321

    
1322
    return 0;
1323
}
1324

    
1325
AVCodec wmav1_decoder =
1326
{
1327
    "wmav1",
1328
    CODEC_TYPE_AUDIO,
1329
    CODEC_ID_WMAV1,
1330
    sizeof(WMADecodeContext),
1331
    wma_decode_init,
1332
    NULL,
1333
    wma_decode_end,
1334
    wma_decode_superframe,
1335
};
1336

    
1337
AVCodec wmav2_decoder =
1338
{
1339
    "wmav2",
1340
    CODEC_TYPE_AUDIO,
1341
    CODEC_ID_WMAV2,
1342
    sizeof(WMADecodeContext),
1343
    wma_decode_init,
1344
    NULL,
1345
    wma_decode_end,
1346
    wma_decode_superframe,
1347
};